FDM vs SLA 3D Printing: The Complete Cost Comparison

Everyone talks about FDM vs SLA in terms of surface finish — resin prints look sharper, FDM prints look more "3D-printed." Fair enough, but if you're running a business instead of a hobby shelf, the question that actually matters is: what does each part cost you to make, start to finish?

The short answer is that resin is more expensive, sometimes a lot more. The interesting part is where that extra cost hides — because it's not just the bottle price. I've seen people quote a job based on material cost alone and then wonder why the SLA batch ate their margin. So let's actually run the numbers, for a single prototype and for a 50-unit batch, and see where the real costs live.

1. Raw material costs

Start with the obvious number:

• Standard FDM filament: PLA, PETG, or ABS runs $16–25 per kilogram. Specialty filaments — flexible TPU, carbon-fiber composites, nylon, ASA — jump to $35–80/kg.
• Standard SLA resin: photopolymer resin costs $25–55 per liter (roughly 1.1 kg). Engineering-grade or specialty resins — tough, flexible, high-temp, castable wax for jewelry, biocompatible dental resin — run $60–300+ per liter.

Gram for gram, standard resin costs 1.5 to 2.5 times what standard filament does. For the specialty materials, the gap gets wider, not narrower.

2. The consumables nobody mentions in the spec sheet

This is the part that actually surprises people switching from FDM to SLA. The plastic itself is only the start.

FDM barely has any. Aside from an occasional nozzle ($1–5) or a stick of glue for bed adhesion, there's nothing recurring. Filament melts, gets deposited, and that's the whole chemistry involved.

SLA comes with a full chemical workflow, and each step has its own running cost:

1. Isopropyl alcohol (IPA) for washing uncured resin off the print — $15–25 per gallon, and it needs replacing once it's saturated.
2. FEP/NFEP release film at the bottom of the vat degrades from UV exposure and peeling forces with every print. $5–15 per sheet, replaced every 10–50 prints depending on usage.
3. PPE — nitrile gloves, goggles, a mask — because liquid resin is genuinely unpleasant on skin and eyes, every single print cycle.
4. The vat itself scratches and clouds over time and eventually needs replacing too.

If you want to model it properly, the per-print SLA material cost looks like this:

$$C_{\text{SLA-material}} = \left( \frac{V_{\text{part}} + V_{\text{supports}}}{1000} \times P_{\text{resin}} \right) + C_{\text{solvent}} + C_{\text{FEP-wear}} + C_{\text{PPE}}$$

Where the FEP wear is simply the sheet's replacement cost divided by the average number of prints it survives. In practice, $C_{\text{solvent}} + C_{\text{FEP-wear}} + C_{\text{PPE}}$ adds an extra $0.50 to $2.00 per print, regardless of how small the part is. None of this shows up when someone quotes you a price-per-liter for resin, but it's real money leaving your pocket every print.

3. Equipment depreciation and energy

The hardware gap is just as real as the consumables gap.

Machine depreciation

A professional-grade FDM printer (think Bambu Lab X1C) costs around $1,200. A professional-grade SLA printer (Formlabs Form 4 class) starts north of $4,500 — and SLA also needs a dedicated wash station and curing chamber, another $200–700 in capital. Spread over a 3-year lifespan at 3,000 running hours per year:

• FDM: $1,200 / 9,000 h ≈ $0.13 per hour
• SLA: $5,000 / 9,000 h ≈ $0.56 per hour

The SLA setup depreciates about four times faster per running hour.

Energy

Here SLA actually wins. FDM printers heat both a nozzle (200–300°C) and a bed (60–110°C), drawing an average of 250–350 W. A desktop SLA/MSLA printer only powers an LED light engine and a small motor — typically 40–80 W. Over a 4-hour print at $0.15/kWh that's roughly $0.14 for FDM vs $0.03 for SLA. Real, but small compared to everything else.

4. Post-processing labor: the hidden profit killer

This is where the gap really opens up. With FDM, you peel the part off the plate, snap off the supports, and in a lot of cases it's done — 1 to 5 minutes of actual hands-on work.

SLA post-processing is a pipeline, not a step:

1. Pull the model off the build plate (messy — it's still wet with resin, gloves on).
2. Wash it in an IPA bath for 10–15 minutes.
3. Remove supports, carefully, while the material is still slightly soft.
4. Dry the part completely, then post-cure under UV for 10–30 minutes.
5. Filter the resin, dispose of contaminated IPA, and wipe down the workstation.

Realistically that's 15–30 minutes of active labor per batch. At a labor rate of $20/hour, the labor component alone is about $1.00 for FDM vs $6.67 for SLA. If you're pricing your own time at all — and you should be — this difference routinely outweighs the material cost gap.

5. Case study: one bracket vs a batch of fifty

Let's price a 50 g functional bracket both ways.

Scenario A: single prototype

For a one-off, FDM is roughly four times cheaper — mostly labor and depreciation, not plastic.

Scenario B: batch of 50

Batching changes the math, and it favors SLA more than you'd expect. An SLA machine cures each full layer across the whole LCD at once, so a plate packed with ten brackets prints in nearly the same time as one bracket — depreciation and wash/cure labor get split across the batch. FDM print time scales almost linearly with part count.

For 50 units, FDM lands around $2.50 per unit while SLA falls to roughly $5.50 per unit. The gap narrows from 4× to about 2× — still a premium, but one that detailed miniatures or dental models can easily carry.

So which one is actually cheaper for your use case?

Choose FDM if:

• you're printing functional, load-bearing parts (PETG, ABS, nylon),
• minimizing per-unit cost and hands-on labor is the goal,
• the parts are large — FDM build volumes are bigger and far cheaper to scale.

Choose SLA if:

• you need intricate detail, smooth surfaces, or fine features (jewelry masters, dental models, miniatures),
• parts must be isotropic, with no weak layer lines,
• your customer is paying a premium that comfortably covers the chemistry and labor overhead.

This isn't really a technology decision — it's a financial one wearing a technology costume. FDM is cheap and fast to clean up after; SLA buys you precision at the cost of chemistry, labor, and a printer that depreciates four times as fast.

If you're trying to figure out which one actually pencils out for a specific job, the 3D Costify calculator compares both technologies side by side — FEP wear, IPA consumption, depreciation, and labor rates included — so the decision is based on numbers, not guesswork. Run your own numbers here.